1. Field of Invention
The present invention relates to a package structure of optical semiconductor integrated circuit device. More particularly, the invention relates to a fabrication method for a package structure of semiconductor integrated circuit having an optical device.
2. Description of Related Art
In the general photoelectric applications, in order to protect the optical device in the form of integrated circuit chip, such as image sensor chip, from being physical damage and environmental contamination, the image sensor chip in practical situation is disposed in a package structure. The package structure has an opening, which is sealed by a transparent cover, so that the image sensor chip can sense the optical signals.
For example, the image sensor chip usually is implemented on a ceramic substrate with protruding pins by using a molding layer. The molding layer usually needs the curing process, so as to firmly implement the image sensing device on the ceramic substrate. After bonding wire and window sealing, the pins are cut to have a proper length. The final structure is achieved and the package process is accomplished.
In the fabrication process about sealing the window, typically, it uses a work process by distributing or molding, so that the molding compound encloses the image sensing device, which is then implemented on the substrate. After then, a transparent cover is disposed over the molding compound, so as to seal the image sensing device between the substrate and the cover. For example, the U.S. Pat. No. 5,811,799 issued to Wu on Sep. 22, 1998 by a title “Image Sensor Package Having A Wall with A Sealed Cover” has disclosed a package structure of image sensor, in which a pre-molded wall is used to package an image sensor chip on a ceramic substrate. The foregoing package structure of the optical device is easily warped, and therefore it needs the ceramic substrate that is rather expansive.
Therefore, it is necessary for the manufacturers in packaging the optical device to provide a package structure of the optical device, so as to reduce the fabrication cost.